matplotlib-users Mailing List for matplotlib

On Wednesday 23 August 2006 02:19, David Goldsmith wrote:
> First, sorry for the long email.
>
> I'm having a segmentation fault problem trying to use plot_date,

Update numpy. Or matplotlib. Or  in matplotlib/dates.py, change line 155 from
remainder = x - ix
 to 
remainder = float(x) - ix

Hi,
I'm trying to make an executable using python 2.4.3 py2exe 0.6.8 Matplot
0.87.4

I've tried the setup file described in
http://starship.python.net/crew/theller/moin.cgi/MatPlotLib
but it didn't work. The error message that I've got was this below.
Is there anybody who know how to make a setup file with
matplotlib.get_py2exe_datafiles() ?

Thanks,
Jenny



C:\DDTAF\Run>DDTAF.exe s
Traceback (most recent call last):
  File "main.py", line 3, in ?
ImportError: No module named pylab

C:\DDTAF\Run>pause
Press any key to continue . . .
<mat...@li...>

-- 
HMRD/ORR/NOS/NOAA <http://response.restoration.noaa.gov/emergencyresponse/>

Here is a snapshot of svn this morning for those wanting to work with
the numpy beta.  Both builds are for python2.4 and windows.

exe: http://tinyurl.com/gf299
egg: http://tinyurl.com/fbjmg

-Charlie

On Wednesday 23 August 2006 2:52 am, Jouni K Sepp=E4nen wrote:
> [Again copying to matplotlib-users; maybe the main developers can
> comment on whether these shortcomings in the getp/setp interface
> should be fixed.]
>
> Hi Derek,
>
> > It does seem as those these settings affect the top and bottom of
> > the graph - I was wondering if it was possible to show tickmarks
> > along the bottom edge but not the top edge?

from pylab import *

a=3Daxes()
a.xaxis.tick_bottom()
show()

[Again copying to matplotlib-users; maybe the main developers can  
comment on whether these shortcomings in the getp/setp interface  
should be fixed.]

Hi Derek,

> It does seem as those these settings affect the top and bottom of  
> the graph - I was wondering if it was possible to show tickmarks  
> along the bottom edge but not the top edge?

I don't think that's directly supported. Here's a hacky way to do it:

     lines = getp(gca(), 'xticklines')
     toplines = [ l for l in lines if getp(l, 'ydata') == (1,) ]
     setp(toplines, visible=False)

How I came up with this: I knew that I wanted to make some of the  
xticklines invisible, so I looked at the list of line objects for  
clues as to what differs between them. They seem to have xdata and  
ydata properties, and ydata is (0,) for half of the lines and (1,)  
for the other half, so it looks like it is the vertical position in  
axis coordinates. (xdata seems to be in data coordinates.)

> And the other property I do not see on the list is the one that  
> shows whether a tick goes "into" the graph or just "out" - in the  
> prc file, there is a line:
>  xtick.direction      : in     # direction: in or out
> but there is no "direction' property?

You're right, there is no obvious property to control this. Here's an  
even hackier way to do this (and one that doesn't look very future- 
proof):

     for l in getp(gca(), 'xticklines'):
         setp(l, 'marker', 5-getp(l, 'marker'))

The line objects have a marker property, which is 2 for some markers  
and 3 for the others... so I guessed that one of them means upwards  
and the other downwards, and checked this guess by flipping the  
xtick.direction parameter and looking again. So subtracting the  
marker from 5 flips the direction.

I wonder how this is done in Matlab?

>     label: any string
>
> which shows me that the Yaxis has a label - in this case a
> string - but I do not see how one can set the font properties
> for the Yaxis label as it is not Text object??

I think you cannot do this with setp alone. Use the ylabel command:

     ylabel('foo bar', fontsize=18)

-- 
Jouni

First, sorry for the long email.

I'm having a segmentation fault problem trying to use plot_date, 
somewhere deep in matplotlib.  After giving up trying to figure out what 
was going wrong from within my "real" code, I wrote a "minimal" sample 
to try to reproduce (or not) the problem; here it is:

import datetime as dt
import wx
import matplotlib as mpl
import wxmpl

class PlotPanel(wxmpl.PlotPanel):
    def __init__(self, parent, *args, **kwargs):
        wxmpl.PlotPanel.__init__(self, parent, wx.ID_ANY, *args, **kwargs)
        self.set_crosshairs(False)
        self.Figure = self.get_figure()
        ax = self.Figure.add_subplot(111)
        ax.clear()
        ax.grid(False)
        zerodate = dt.datetime(2001,2,15)
        zero = mpl.dates.date2num(zerodate)
        x = range(int(zero), int(zero)+11)
        ax.plot_date(x,x) # Problem line; works fine with plot instead 
of plot_date
        self.draw()

class MainFrame(wx.Frame):
    def __init__(self, *args, **kwargs):
        wx.Frame.__init__(self, *args, **kwargs)
        self.PlotPanel = PlotPanel(self)
        self.MainBox = wx.BoxSizer(wx.VERTICAL)
        self.MainBox.Add(self.PlotPanel, 1,  wx.EXPAND )
        self.SetSizerAndFit(self.MainBox)

class App(wx.App):
    def OnInit(self):
        self.frame = MainFrame(None)
        self.SetTopWindow(self.frame)
        self.frame.Fit()
        self.frame.Show()
        return True

if __name__ == "__main__":
    print wx.__version__
    print wxmpl.__version__
    print mpl.__version__
    app = App(0)
    app.MainLoop()

This code runs fine with plot instead of plot_date (just like my 
original code with the same substitution).  But with plot_date, I get 
(please note the versions I'm using):

wx.__version__ =  2.6.3.3
wxmpl.__version__ =  1.2.7
matplotlib.__version__ =  0.87.4
Traceback (most recent call last):
  File "debugplot_date.py", line 40, in ?
    app = App(0)
  File 
"//Library/Frameworks/Python.framework/Versions/2.4/lib/python2.4/site-packages/wx-2.6-mac-unicode/wx/_core.py", 
line 7700, in __init__
    self._BootstrapApp()
  File 
"//Library/Frameworks/Python.framework/Versions/2.4/lib/python2.4/site-packages/wx-2.6-mac-unicode/wx/_core.py", 
line 7352, in _BootstrapApp
    return _core_.PyApp__BootstrapApp(*args, **kwargs)
  File "debugplot_date.py", line 30, in OnInit
    self.frame = MainFrame(None)
  File "debugplot_date.py", line 23, in __init__
    self.PlotPanel = PlotPanel(self)
  File "debugplot_date.py", line 18, in __init__
    self.draw()
  File 
"/Library/Frameworks/Python.framework/Versions/2.4/lib/python2.4/site-packages/wxmpl.py", 
line 1189, in draw
    else:
  File 
"/Library/Frameworks/Python.framework/Versions/2.4/lib/python2.4/site-packages/matplotlib/backends/backend_wxagg.py", 
line 61, in draw
    FigureCanvasAgg.draw(self)
  File 
"/Library/Frameworks/Python.framework/Versions/2.4/lib/python2.4/site-packages/matplotlib/backends/backend_agg.py", 
line 391, in draw
    self.figure.draw(renderer)
  File 
"/Library/Frameworks/Python.framework/Versions/2.4/lib/python2.4/site-packages/matplotlib/figure.py", 
line 532, in draw
    for a in self.axes: a.draw(renderer)
  File 
"/Library/Frameworks/Python.framework/Versions/2.4/lib/python2.4/site-packages/matplotlib/axes.py", 
line 1045, in draw
    a.draw(renderer)
  File 
"/Library/Frameworks/Python.framework/Versions/2.4/lib/python2.4/site-packages/matplotlib/axis.py", 
line 548, in draw
    majorLabels = [self.major.formatter(val, i) for i, val in 
enumerate(majorLocs)]
  File 
"/Library/Frameworks/Python.framework/Versions/2.4/lib/python2.4/site-packages/matplotlib/dates.py", 
line 369, in __call__
    return self._formatter(x, pos)
  File 
"/Library/Frameworks/Python.framework/Versions/2.4/lib/python2.4/site-packages/matplotlib/dates.py", 
line 247, in __call__
    dt = num2date(x, self.tz)
  File 
"/Library/Frameworks/Python.framework/Versions/2.4/lib/python2.4/site-packages/matplotlib/dates.py", 
line 205, in num2date
    if not iterable(x): return _from_ordinalf(x, tz)
  File 
"/Library/Frameworks/Python.framework/Versions/2.4/lib/python2.4/site-packages/matplotlib/dates.py", 
line 156, in _from_ordinalf
    hour, remainder = divmod(24*remainder, 1)
ValueError: need more than 0 values to unpack

Using winpdb, I determined that this line in dates.py get called 13 
times before, on the 14th time, it causes a "communication failure" 
between winpdb and the code.

Any ideas what's up?  Thanks in advance,

DG

PS: I'm on a Mac, running system 10.4.7 with Python 2.4.3 (#1, Apr  7 
2006, 10:54:33) [GCC 4.0.1 (Apple Computer, Inc. build 5250)] on darwin

Briefly, is there a way to get a callback in the event that the  
canvas has been redrawn (e.g. from a zoom or pan)?

matplotlib 0.86.2
python 2.4.1
wxPython 2.6.2.1
Mac OS X.4.7

I draw a circle at a certain point. I let the user drag that point to  
a new location. However, if the plot is redrawn for any reason, I  
have to redraw my circle in a new position. I can't seem to find any  
way to get notified of a redraw.

Figure.add_axobserver() isn't fully implemented as far as I can tell  
since it only notifies for a artist deletion or a call to sca().
Axes.connect() doesn't work either because there's no way to set emit  
in a class-wide scope and consequently calls made to set_xlim made by  
the toolbar do not trigger an event because they lack the emit  
keyword in their calls. Here's the relevant code from axes.py.

   def set_xlim(self, *args, **kwargs):
         # .....
         emit = popd(kwargs, 'emit', False)
         # .....
         if emit: self._send_xlim_event()
         return vmin, vmax

I've been trying to accomplish this without editing matplotlib  
package code. Is there a way I could override Axes.set_xlim() in  
order to insert "emit=True" into the arguments?

Maybe there's a better way to do what I'm doing?


Thanks,

R.